The present invention relates to an endoscopic apparatus with a laser light conductor, particularly for the irradiation of bladder tumors in man. The present apparatus is adapted to cause the complete necrosis of the tumor without the need for a perforation of the bladder wall.
Prior art devices of the above mentioned type are described in the periodicals: "Fortschritte der Medizin", Number 1, Volume 95, pages 3 to 7; and in "aktuelle urologie", Volume 9, (1978), pages 271 to 274. In the prior art devices a conventional cystoscope is combined with a light conductor. Such devices have been used successfully for the above mentioned treatment of bladder tumors. However, it has been found that substantial difficulties have been encountered in obtaining a precisely defined laser light output power of a sufficient size available at the output end of the light conductor. Further, it is difficult to steer or train the light beam substantially without loss of power onto a tumor to be treated at any desired location on the inner surface of the bladder wall.
For the last mentioned purposes deflecting mirrors have been used. However, such mirrors have the disadvantage that they are heated up by absorbing the laser radiation. Such heat-up has resulted in the destruction of the deflecting mirror when higher laser energies have been used which are suitable for the tumor treatment.
It has also been tried heretofore to deflect the laser beam by means of a glass or quartz prism rather than by means of a mirror. However, in such an arrangment the light conductor output is covered by a glass or quartz prism or with a window for a so-called "prograde" irradiation. The glass or quartz window as well as the movable prism both require special auxiliary means for keeping these components clean just directly prior to the laser irradiation, for example by means of a water and air rinsing. Even small contaminations cause an instantaneous burn-in on the mentioned components and thus quite frequently a destruction of the apparatus.
It is also necessary in devices without prism or window to keep the output end of the light conductor such as a light conducting fiber clean during its use inside the bladder because the liquid in the bladder may soil the output end, whereby the capability of the light conductor to function properly is impaired and the laser irradiation is correspondingly impaired. The endoscopic apparatus then has to be removed from the urinary tract for a cleaning and thereafter it must be introduced again which should be avoided since the procedure may be rather painful.